The present invention relates to a non-contact type data transmission system between electronic apparatus and, more particularly, to a capacity coupling type data transmission circuit for portable electronic apparatus.
A conventional non-contact type data transmission system for electronic apparatus is typically of an optical or magnetic coupling type. The optical coupling type system comprises a light emitting diode in a transmitting unit and a phototransistor in a receiving unit for receiving light from the diode. The magnetic coupling type system is comprised of a magnetic sensor and a pick-up coil.
Since the signal processing system of each apparatus is electrically isolated from that of the other, the operating voltage level of the electronic apparatus can be converted. However, they are driven with currents which results in large power being consumed and thus a complex circuit is needed. Therefore, they are not suitable for a portable electronic apparatus driven with a small voltage, for example, provided from a battery.